Hydraulic screw jack



Sept. 18, 1951 y F, C, Foss 2,568,437

HYDRAULIC SCREW JACK Filed March 18, 1.947 2 Sheets-Sheet l I Inventor 58 i Freeman C. Foss 9 Y By 56 I W /l/f//j f' W y Att-orneys Sept. 18, 1951 F, C, FOSS 2,568,437

I HYDRAULIC SCREW JACK m Filed March 18, 1947 2 sheets-sheet 2 Inventor Freeman Cy Foss Fig. 5

5 6 E meys Patented Sept. 18, `1951 UNITE-1DL STATES 'ATENT OFFICE 2,568,437 f i l HYDRAULIC SCREW JACK Freeman G. Foss, 1win.Fal1s, IdahoA Application March 18, 1947, Seri'al No. 7 35,467

2` Claims. (Cl. 254--84) `This invention relates generally to hydraulic'. jacks, and more particularly to a hydraulic jack adapted for suspension on an= overhead support-` ing member such as an I-beam, the jack being adapted for hand operation, and for convenient pre-adjustment preparatory to the actual pressure operation.

It is an object of this invention to provide. a jack of this general character which can be adjusted by turning a hand# wheel secured to the piston portion of the jack. whereafter a hand operated` hydraulic pump is used to move a load secured to the body portion of the jack which constitutes the cylinder wherein said piston moves.

Another object of this invention is to provide a simple means of releasing the jack, this releasing meanslbeing combined with a gauge which maybe made to read either inweight or pressure units, this latter feature being of considerable importance as asafety factor.

Another object ofr this. invention is to provide in a device of this character, ahydraulic system which isA completely closed and in which the elements are so arranged' that airis effectively excludedifrom the pump.

Another object of this inventionl isto so design a hydraulicV jack that the majority of thei work ing parts, excepting exterior portionsoff the pump and. control valve, are grouped together on the piston head in such manner asto line-readily accessible for inspection, adjustment and' repair.

And a last object to be specifically'mentioned is to provide a device of thischaracterwhich is relatively inexpensive and completely practicable to manufacture, simple'. and: easy to install and use, and which is suiciently sturdy to` give generally eiiicient and durable: service..

With these. andvother objects. definitely in. view, thisinvention` resides in. certain novelr features of construction, combination and. arrangement ofparts and portions as.` will be; hereinafter described in detail andL particularly set forth in theappendedclaims, reierence being had to the accompanying drawings which form a material part of this application., and in; which :A

Figure l is a top plan. viewl of thisjackaopera` tively mounted on` a pair ofstandard' angles, dis:- posed back to back'A as conventionally` usedtoicomprise means. in the overheadv structure.-V of build.-l ings of the type wherein a devicefof the type described herein likely: to. bei used;

Figure 2` is a side elevationalv-lew ofthis invention, thesuppor-ting angles beingY shown in!A section,l to show how this jacle mounted on' overheadstructure, and` a; portion-ofthewbracketV lili;

member of the jack being broken away to showv underlying structure in section and in elevation; Figure 3` is another side elevational' view of the same structure as that shown in Figure 2, a portion of'the body memberV of the jack being broken away;

Figure 4 is an enlarged perspective view', fragd mentary in character, of theA central top` portion of the jack with the gauge; valve and@ a portion of the handle being broken away;

Figure 5 is a vertical sectional View, the view being substantially a `transverse section on the center line of Figure 2, the'igure being enlarged, broken and fore-shortened to delete the bracket portion and the valve and handle* mechanism at theY top of the jack, and

Figure 6 is a horizontal' cross sectional View taken on the line G-Bin Figure 5.

Similar characters of reference designate similar or identical parts and portions throughout the several views o the drawings and throughout' the speciication.

Reerr-ingnow to the drawings in` detail) it will! be noted that this invention is proposed to be used? with overhead structure, preferably com--` prisi'ngtwo angles l`0'- and t2", or I-be-ams, ar-r rangedfback tobackA and spaced apart to allow theA insertion therebetween of the bracket supporting member; generally represented by the numeral I4, and including aninteriorly threaded sleeve or collar member I6, a transverse plate member I8- and upstanding flanges 20 adapted to spa-n' the lower edges of the angles IIJ` and I2f`, and to tie the rollers22. These rollers 2-'2l are freely rotatably mounted on short stub axles 2-'4" securedto the uprightflanges 20 and having` enlarged headsto bear against one side of' each ofk the rollers 22, a spacer sleeve 2-6 beingl provided between each roller and thecorrespondingA upright ange; all as illustrated inv Figure 2; It will', of` course, be understood that theseirollers 2-2 will each contact a ledgef ofthe' angles IG" andl2 and that" the bracket assembly, as a whole, provides for adjustability of the jack along the overhead structure'provid'ed in the building wherein the' jack`A is to be used.

Ireference isf now` had to-Figure 5, :it will be clear how the piston 28'` isiprovided with anupwardly extending and exteriorly threaded por-- tion 3U to engage the interiorly threaded mem-i ber I6 of the above described bracket, and it will may behsecured to the extension 30-bymean's'oif 3 set screws 34, and the structure of this wheel will be more clearly understood if reference is had to Figure 4 wherein the spokes 36 of the wheel are shown integrally connected to a central disc 38, upon which several operating units are mounted, as described hereinafter.

The lower end of the piston 28 is interiorly threaded to receive the exteriorly threaded boss portion 40 of the piston head generally indicated by the numeral 42. The piston 28 is hollow throughout theV major portion of the lensgth thereof and the piston head 42 closes the lower end of this hollow piston. The piston head is provided with a leather packing 44, held in place against the outer face of the head by a heavy washer member 46 and a stepped plug 48. Figure shows clearly how a stud portion of this plug 48 is exteriorly threaded to be screwed into the lower end of a similarly threaded aperture in the piston head 42. This stud portion 50 is centrally drilled to provide fora stepped central aperture the lower end 52 of which communicates with the chamber 54 between the lower end of the piston head 42 and the lower closed end 56 of the body portion 58, it being understood that this cates with the interior of the piston 28 and at the upper end this tube communicates with the valve ||0, it being understood that the valve ||0 controls ow from the tube ||2 to the tube |20. When the device is assembled, the piston 28 is guided and prevented from withdrawalfrom the' of its travel under the pressure of liquid forced body portion 58 has a cylindrical bore B0 to accommodate the piston portions described above.

VThe channel 52 communicates with the enlarged co-linear channel 62 and one end of the spring 64 is housed in this enlarged portion 62, while the upper end of this spring extends into a co-linear recess 66 to bias the ball 68 into a position closing the-channel '10. The upper end face of the portion 40 of the piston head is drilled and tapped at three points to receive the threaded ends of the force pump piston cylinder 12, the pump inlet stand pipe 'I4 and the lower end of the pressure release tube 16. In each case the above recesses are 'extended downwardly beyond the threaded portions thereof to provide the chambers 18, 80 and 82, respectively. The chamber S2 communicates directly through the channel 84 with the chamber 86, while the chamber 'I8 communicates with the chamber 86 through the channel 88 and the ball valve 68. The inlet stand pipe 14 communicates with the channel 10 and is normally closed by the spring biased ball valve 90.

The force pump piston 92 is provided at its lower end with a packing 94 held in place by any suitable means represented at 96. The upper end of the piston, that is, the shank portion 08 extends centrally of the extended portion of the piston, through any suitable gland structure,

`represented at 60 to terminate in the bifurcated end |02, represented in Figures 3 and 4. In order to reciprocate the piston 92, the bifurcated end |02 is secured by a pin |04 to the lever |06, at a point intermediate the ends thereof and one end of this lever is pivotally mounted on a suitable bracket member |08 secured to the disc 38.

To` provide for release of the pressurized fluid from the chamber 54, when it is desired to release the jack, a manually operable valve ||0 is secured to the upper end I2 of the release tube 16, that is, in the portion of this tubewhich extends through the disc 3-8, so that this valve is conveniently accessible from above the wheel 32. It ispreferred that a T-joint 4 be used to facilitate the installation of this valve |0 and a pressure gauge H6, which will indicate the pressure applied. A hydraulic fluid filler hole, closed by' ascrew cap I8, is provided in the disc 38 and will preferably communicate with the pressure release return tube |20, which latter communi-- into the chamber 54. In this connection, it may be noted that transversely disposed channels |24 maybe provided in the stepped packing retaining nut 48, Vto direct a portion of the flow of the hydraulic fluid outwardly against the skirt portion ofthe packing 44, and theV lower end 56 of the body member may be shaped in any preferred manner and provided with any suitable attaching means, whereby the loads to be lifted or compressed may be, engaged.

The operation of this invention will be clearly understood from a consideration of the foregoing description of the mechanical details thereof, taken in connection with the above recitation of objects sought to be achievedthereby, but, in recapitulation, it maybe noted that hydraulic iiuid'is inserted into the jack throughthe means represented at V| I8 andsuicient hydraulic fluid is insertedsto substantially fill thecavities within thejack, the ,hollow portion of the piston 28 serving as a reservoir for the fluid. Whenthe piston 2 8 is to be movedrelative to the body member 58, thevalvelljis closed and the handle |06 ,is manually moved upwardly and downwardlyto cause the piston 92 to force hydraulicY sure is to be released the manually operable valveV 0 is'opened, allowing the hydraulic fluid to escape fromthe chamber 54 through the channels 52, 84 and through the pressure release Ytube 'i6 and the pressure vreturn tube |20. In this connection, it should be noted that the pumping mechanism will at all times be immersed in hy draulic fluid and that air will not be introduced intoV thelclosed vsystem provided in this device, this feature is thought to .be very important inasmuch as the inclusion Vof `the relatively elastic air in aehydraulic pump jack causes the pump' to become Asubstantially inoperative.

Though Ythere has been shown a particular embodiment ofl this invention, this application is not limited tothis particular embodiment, but it vis desiredto include in the scope of this invention theconstruction,combination and ar-i rangement of parts and portions substantially as set forth in the appended claims.

Having thusldescribed this invention what isY claimed as'new and desired to be secured by Letters Patent is:

1. A hydraulic'jack'including ,a body member having acylindricalbore closed at one end, a

piston slidablymounted within said bore andhaving achanneLleadillg into said bore, said pistonhaving airextending hollow portion. con;-`

- taining hydraulic fluid, a force pump associated threadedly mounted thereon, xed rail structure having flanges, said bracket having a flat portion in superficial sliding relation with said rail structure, rollers on said bracket whereby the bracket is suspended from said rail structure, and a hand wheel xed coaxially on said extending portion.

2. A hydraulic jack including a body member having a cylindrical bore closed at one end, a piston slidably mounted within said bore and having a channel leading into said bore, said piston having an extending hollow portion containing hydraulic fluid, a force pump associated with said piston to pump said hydraulic fluid from said hollow portion through said channel into said bore, and means to release and return the pumped iluicl to said hollow portion, said extending portion of the piston having a bracket threadedly mounted thereon, fixed rail structure having flanges, said bracket having a nat portion in superficial sliding relation with said rail struc ture, rollers on said bracket whereby the bracket is suspended from said rail structure, and a hand wheel xed, coaxially on said extending portion, said wheel including a central disc secured on the upper end of said extending portion, said force pump having an actuating handle operatively mounted on said disc, and said means including a manually operable valve on said disc and a channel by-passing said force pump and controlled by said valve.

FREEMAN C. FOSS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 151,670 Ojeda June 2, 1874 569,574 Caldwell Oct. 13, 1896 874,699 Nelson Dec. 24, 1907 941,870 Gathmann Nov. 30, 1909 1,047,007 Drugan Dec. 10, 1912 2,003,648 Frye et al June 4, 1935 

